Update build.func

fixes https://github.com/tteck/Proxmox/issues/2356

misc/build.func

@@ -572,7 +572,11 @@ EOF
   pct start "$CTID"
   msg_ok "Started LXC Container"
   if [ "$var_os" == "alpine" ]; then
-    sleep 2
+    sleep 3
+        pct exec "$CTID" -- /bin/sh -c 'cat <<EOF >/etc/apk/repositories
+http://dl-cdn.alpinelinux.org/alpine/latest-stable/main
+http://dl-cdn.alpinelinux.org/alpine/latest-stable/community
+EOF'
     pct exec "$CTID" -- ash -c "apk add bash >/dev/null"
   fi
   lxc-attach -n "$CTID" -- bash -c "$(wget -qLO - https://raw.githubusercontent.com/tteck/Proxmox/main/install/$var_install.sh)" || exit